1
vote
3answers
61 views

Best approach for Legal/Natural can have many Orders

I'm working on this model: where as you may see one NaturalPerson can have many Order and the same for LegalPerson the only difference between NaturalPerson and LegalPerson are a few so in that ...
2
votes
1answer
387 views

Relationships between subtypes of an entity

I have a very big (hundred of milions rows) table which represent an entity (event) having many subtypes (different kind of recorded events). Each row is identified by an id (obj_id) and has an ...